Digital Dissolved Oxygen DO Meter Pressure Salinity Monitor Tester Range: 0~199.9% / 0~19.99 PPM / 0~19.99 mg/I Accuracy: 1.5% F.S Resolution: 0.1% / 0.01 PPM / 0.01 mg/I Temperature Measurement Range: 0~50 C ;Accuracy:  0.3 C ;Resolution: 0.1 C Salinity Measurement Range: 0.0~50.0 ppt / Resolution: 0.1 ppt; Barometric Pressure: 500~1499 mmHg / 66.6~199.9 KPa; 99 Memory; Data hold function Pressure Resolution: 1 mmHg / 0.1 KPa; Operating Temperature : 0~50 C / Humidity &lt; 80%; Storage Temperature : 0~60 C / Humidity &lt; 90% ; Operating Features: Manually Salt / Baro Compensation/ Memory/ IRDA/ Real Time in Year/Month/Date and Hour/minute/Seconds interchangeably